Apparatus for drawing wires.



E. HURWITZ.

I APPARATUS FOR DRAWING WIRES.

APPLICATION IILED JAN.19,1912.

1,023,316, Pate nted Apr. 16, 1912.

7-. :IIIIIIIIIII rlllllllllllffig K Witnesses: Inventor:

v Eugen Huryvitz, v b

STATES PATENT OFFICE.

BUG HUBWITZ, OF BERLIN, GERMANY, ASSIGNOR TO GENERAL ELECTRIC COM- PANY, A CORPORATION OF NEW YORK.

Specification of Letters Patent. V

Patented Apr. 16, 1912 Application Med January 19, 1912. Serial No. 672,196.

To all wlwm it may concern:

Be it knownthat I, EUGEN Honwrrz, a subject of the Emperor of Germany, residing at Berlin, Germany, have invented certam new and useful Im rovements in Apparatus for Drawing ires, of which the following is a speclfication.

My invention relates to drawing wires from metals such as tungsten which should be heated during the drawing operation in order to increase the ductility? For this purpose, the wire may be heated either by a flame or by passing an electric current through the portion of the wire just entering the die.

he object of my'invention is to insure that the wire is properly heated but not overheated even though the speed of drawin may be varied considerably.

y invention consists in providing means for'automatically varying the heat energy supplied to the wire upon a variation of the speed with which the wire is drawn through the die. Thus the faster the wire is drawn, the more heat is supplied to the wire, so as to bring it to the proper temperature by the time it reaches the d1e.

The accompanying drawing shows diagrammatically one suitable arrangement of apparatus for carryin out my invention.

If the wire is heate by means of an electric currentthe temperature may easily be adapted to the particular thickness of wire, the particular speeds of drawing, the properties of the material, etc., and by calculation it may be determined how many amperes should be sent through how great a length of wire of a certain thickness when drawn at a given speed, in order to obtain the proper temperature at the die. The temperature of the wire at the die may be regulated both by 'var ing the amount of current supplied to the wire, and by varying the length of the wire to which the current is supplied by shifting one terminal of the current supply toward or away from the die. When meta lic dies are used the second terminal of the current supply may be formed by the die itself. If non-conducting bodies are employed as dies, such as sapphires, diamonds, etc., then the second current conductor is placed just beyond the die. In the -latter case since the end of the wire that has been drawnthrough the die isvsmalle'r than the one which has not yet been drawn through and since with the same current intensity the smaller end reaches a higher temperature than the coarser end which has not een drawn, it is desirable to make provision for cooling the smaller end. This may be done, for example, by directing a current of air or other gas against the piece of wire as it comes out from the die. The current conductors may, with coarser wires, be formed by metallic brushes, while with smaller wires metallic drums may be employed about which the wire is carried one or more times. Metals which tend strongly to oxidation may be pr otected from the access of air by beinglcarried through a tube or casing durng t e heating operation, which tube or casm is filled with an inert gas.

11 the accompanying drawing which shows diagrammatically one suitable arrangement, 'A represents the wire, and B the'die.

C, C represent reels on, and from which, respectively, the wire is being wound.

D represents diagrammatically the' armature o a small electric motor driving the reel C. The motor D is represented as a shunt motor, its field winding being indicated at d.

F represents a field rheostat for regulating the speed of the motor.

E represents the source of the current supply.

g, g represent brushes or other suitable means for conveying current to and from the wire A. If the die B is of steel the brush 9 may be omitted and the die itself constitute the second terminal. A rheostat H is placed in circuit with the wire and is higher speeds and to decrease it for lower speeds.

It represents a permanent resistance in the circuit of the wire. If the wire is readily oxidizable, the heated'portion enterin the die may be inclosed in a suitable casm J connected to a source of inert gas throug a pipe 7'. The pressure in this casing may be slightly above atmospheric pressure so that whatever leakage occurs through the casing will be outward. If non-conducting dies are used so that the brush g is employed the wire leaving the die may be cooled by a blast of air or inert gas issuing from the nozzle K which is connected by a pipe 70 to a suitable source of pressure.

I do not desire to limit myself to the particular construction and arrangement of parts shown and described, but aim in the appended claims to cover all modifications which are within the scope of my invent-ion.

What I claim as new and desire to secure by Letters Patent of the United States, is-

1. In an apparatus for drawing wire, in combination with the drawing die, driving means for drawing the wire through the die, means for heating the wire immediately before its passage through the die, means for varying the speed of the driving means, and means for automatically varying the heat energy supplied to the wire upon a variation of the speed of the driving means.

2. In an apparatus for drawing wire, in combination with the drawing die, driving means for drawing the wire through the die, means for supplyin electric current to the portion of the wire ust entering the die to heat it, means for varying the speed of the driving means, and means for automatically varying the current supplied to the wire upon a variation of the speed of the driving means.

3. In an apparatus for drawing wire, in combination with the drawing die, electrically operated drivin means for drawing the wire through the ie, means for sup lying current to the portion of the wire ust entering the die to heat it, switch contacts for varying the speed of the driving means, switch contacts for varying the amount of current supplied to the wire, and o erative connections between the two sets 0 switch contacts for insuring their simultaneous operation.

In witness whereof, I have hereunto set my hand this 4th day of January, 1912.

EUGEN HURWITZ. 

